Desire & wellbeingEarly human evidence
Maca root
Lepidium meyenii
Small placebo-controlled trials have explored maca for sexual desire and sexual wellbeing. Some reported improvements, but sample sizes were modest and results should be interpreted cautiously.
- ✓ 12-week placebo-controlled trial
- ✓ Benefit observed from week 8
- ✓ More research is needed
View published abstract ↗Gonzales et al., Andrologia (2002)
Physical performanceLimited human evidence
Black ginger
Kaempferia parviflora
Human studies of standardised black ginger extracts have examined grip strength, physical fitness and endurance. Findings vary by extract, dose, population and duration.
- ✓ Randomised controlled design
- ✓ Fitness outcomes studied
- ✓ Extracts are not interchangeable
View published abstract ↗Promthep et al. (2015)
Alertness & response timeMixed human evidence
Guarana
Paullinia cupana
A systematic review found a small improvement in response time across acute studies, without a clear improvement in accuracy. It remains unclear how much is attributable to caffeine.
- ✓ 8 placebo-controlled studies
- ✓ 328 participants
- ✓ Small response-time effect
View published abstract ↗Hack et al., Nutrients (2023)
Traditional botanical useInsufficient direct evidence
Epimedium
Epimedium species
Epimedium and its flavonoids have been studied in humans for selected outcomes, limited direct clinical evidence on intimacy benefit from Epimedium itself.
- ✓ Human safety data exist
- ✓ Outcome-specific evidence
- ✓ No overextended claims
View published abstract ↗Yong et al. (2021)